Because after the crash of 1983, video games ceased to be a thing for grownups. People of all ages used to play at the arcades and with Atari consoles, but the NES had to be Trojan horsed into the US as a toy to disguise it as “totally not a video game console, I promise”. So console gaming was rebranded as a pastime for kids, and when it became big enough, not to mention expensive enough, parents suddenly became concerned. Add to that the tales of “demonic” imagery in games such as JRPGs and Castlevania and you also had concerns about video games corrupting the young and making them easy prey for cults - and that’s with Nintendo doing their best to remove blatant references to any sensible topic, like religion or alcohol. The irony, of course, is that the parents of the time probably used to spend a lot of time at the arcades just a decade or so before.
Nowadays video games are again a pastime for all ages and they’re so high-tech and realistic that nobody has much reason to relegate their console to the man-cave. Few parents also know what to do whit their children when they’re around, so a Nintendo anything is a very good aid in getting some quiet time in the house.
There was also a very compelling argument of economic nature in the rage of parents at the time. Game cartridges were goddamn expensive, games were much shorter than today, there was no online multiplayer, and help lines for gamers were a thing and they cost money that today would be included in your regolar Internet bill. The mom concerned about the need for a new console to play new games did have some kind of a point at the time - you didn’t need a new VCR to watch new films, after all. I guess their reasoning was along those lines.
My grandmother was a very religious woman, and if she could just have her way in my upbringing, I’d probably never even have a NES. She loathed seeing me play games; she was adamant that every single thing wrong in me - from the occasional bad grade in school to me developing nearsightedness - was the fault of video games. I guess that me getting a Game Boy one summer was the final nail in the coffin of her hope that I could at least not play video games when away from home.